This project is directed to the reduction of the morbidity and mortality associated with alcohol use, alcohol abuse and alcoholism. It falls in the area of prevention. Problem drinkers, alcoholics, and other drug users are a class of Americans who present a major highway safety problem because of their high involvement in highway accidents. Suspension of the driver's license is a frequently used penalty when these individuals are convicted of driving while impaired. Because the probability of being apprehended for driving without a license is very low, many offenders continue to drive despite revocation. To avoid interfering with the ability of the individual to earn a living, the court will often issue a restricted license which allows driving to and from work or while on the job, but not during evening hours when most alcohol-related accidents occur. Improved supervision of license restrictions could reduce the frequency with which they become involved in accidents. This study is designed to determine whether an electro-mechanical device ("Autotimer") attached to the car of an offender can monitor his driving to ensure that it conforms to the hours of the day set by the court. The cost effectiveness of this monitoring system will be determined in relationship to the current practice of permitting unsupervised restricted licenses to be issued to drunk driving offenders.